PROJECT ABSTRACT Short bowel syndrome (SBS) is a major clinical problem affecting newborns, children and adults, for which there is currently no known cure. The disorder results from the functional or anatomic loss of extensive segments of small intestine rendering the intestinal absorptive capacity severely compromised. SBS is clinically defined by malabsorption, diarrhea, steatorrhea, fluid and electrolyte disturbances, as well as malnutrition. SBS has an overall 5-year survival of 70%, and in newborn infants with less than 10% of expected intestinal length, 5-year survival is only 20%. Current treatment options are inadequate and associated with severe complications and death. Patients with SBS require total parenteral nutrition (TPN) to survive. Currently, over 20,000 SBS patients per year are on home TPN in the US alone. Annual costs of home TPN exceed $300,000 per year per patient ($6 billion/year). In addition to the expense of TPN, its use is associated with numerous central venous catheter- associated infectious and thrombotic complications, resulting in additional high costs. Thus, SBS represents an extremely costly, and deadly, burden to society. At present, the treatment for SBS is mainly supportive. Although small bowel transplantation is an option, the results are suboptimal, with 1-year and 4-year survival rates of 90% and 60%, respectively. In addition, small bowel transplantation requires life-long immunosuppression that causes numerous substantial secondary complications. Novel approaches for the treatment of patients with SBS are critically needed. Our approach to this unsolved medical problem is the production of tissue-engineered intestine (TEI) using the patient?s own intestinal cells seeded onto a biodegradable scaffold, resulting in a novel solution to this unmet clinical need. Our Phase I funding allowed us to develop successful standard operating procedures for the production of TEI in rodents. In this Phase II project we will we will expand upon our Phase I findings in a large animal model and will accomplish the following specific aims necessary to move towards commercialization: Aim 1) To successfully produce tissue engineered intestine in pigs using freshly isolated ISC- containing organoids. Aim 2) To optimize production of tissue engineered intestine in pigs using in vitro cultured and expanded enteroids. Aim 3) To successfully anastomose porcine tissue engineered intestine in line with host intestine. This Phase II STTR project will allow us to continue the path to developing a fully functional human tissue engineered intestine. We have assembled a world-class team that includes a leading pediatric surgeon, a leading pediatric institute where we can do our first-in-man study, and a pioneering small-business with expertise in scaffold design that will allow us to build the strategic partnerships with large medical device companies needed to successfully commercialize this urgently-needed, life-saving technology.